1. Field of the Invention
The invention relates to a light emitting diode (LED) lamp tube, more particularly to a LED lamp tube capable of providing uniform illumination without generating glare.
2. Description of the Related Art
Light emitting diode (LED) lamp tubes have less in power consumption and are brighter than fluorescent lamp tubes. Referring to FIG. 1, a conventional LED lamp tube 1 comprises a lamp unit 11, and a tubular enclosure 12. The lamp unit 11 includes a circuit board 111, a plurality of rows of LEDs 112 electrically connected to the circuit board 111, and two connectors 113 electrically connected to the LEDs 112. The circuit board 111 divides an inner surface of the tubular enclosure 12 into a light-receiving portion and a non-illuminated portion. Each row of LEDs 112 includes three LEDs 112 that are arranged along a transverse direction (Y) of the tubular enclosure 12.
However, the conventional LED lamp tube 1 encounters a problem during use in that glare is generated that can irritate users' eyes and make the users uncomfortable and dizzy due to the fact that the number of beams of light passing through the light-receiving portion of the tubular enclosure 12 reduces gradually from a middle portion of the light-receiving portion to junctions between the light-receiving portion and the non-illuminated portion.
In particular, as illustrated in FIG. 2, with respect to an axial position of the lamp tube 1, the brightness of regions (b) is greater than that of each region (a), and smaller than that of region (c). As such, the brightness of the light-receiving portion of the tubular enclosure 12 is not uniform, and glare is generated.
Referring to FIG. 3, in Taiwanese Patent Publication No. M330422, an LED lamp tube has a structure similar to that of the previously described lamp tube. The enclosure 12 has an inner peripheral surface formed with a plurality of protrusions 13. The protrusions 13 extend along an axial direction (X), and are arranged along a circumferential direction of the enclosure 12. Due to the presence of the protrusions 13 of the enclosure 12, uniformity of illumination can be increased and glare can be decreased.
However, the above configuration cannot solve effectively the glare problem. That is, uniform illumination cannot be achieved.